VIVID Ultimate Flashing Safety Collar-Size Small Blue Illuminated with Rechargeable Battery-FREE PET TOY WITH PURCHASE OF THIS PRODUCT! Small Collar (10-14: long and 1" W) Correct Collar Size: The sizes listed above indicate the maximum size with the buckle fastened. Measure your pet's neck before ordering. You may wish to add 1" - 2" to the measurement for your dog's comfort. Rechargeable battery Glow in the dark reflective strips Light sensitive setting that automatically switches collar on in the dark